Quadratic Equations:
Mr Tan is 5 times as old as his son, Alex. Two years ago, the sum of the squares of their ages was 1114. Find their present age.

Let x be the present ago of Mr Tan's son. So, Mr Tan is no 5x years old
Two years ago, the age of Mr Tan is 5x-2 and the age of his son is x-2.
From the question '' the sum of the squares of their ages was 1114.'', we get
(5x-2)^2 + (x-2)^2 = 1114 , which is a quadratic equation.
Got it?